/* * Copyright (C) 2011-2014 Matteo Landi, Luigi Rizzo. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * $FreeBSD: stable/11/sys/dev/netmap/ixgbe_netmap.h 343771 2019-02-05 10:33:22Z vmaffione $ * * netmap support for: ixgbe (both ix and ixv) * * This file is meant to be a reference on how to implement * netmap support for a network driver. * This file contains code but only static or inline functions used * by a single driver. To avoid replication of code we just #include * it near the beginning of the standard driver. */ #include #include /* * Some drivers may need the following headers. Others * already include them by default #include #include */ #include void ixgbe_netmap_attach(struct adapter *adapter); /* * device-specific sysctl variables: * * ix_crcstrip: 0: NIC keeps CRC in rx frames (default), 1: NIC strips it. * During regular operations the CRC is stripped, but on some * hardware reception of frames not multiple of 64 is slower, * so using crcstrip=0 helps in benchmarks. * * ix_rx_miss, ix_rx_miss_bufs: * count packets that might be missed due to lost interrupts. */ SYSCTL_DECL(_dev_netmap); static int ix_rx_miss, ix_rx_miss_bufs; int ix_crcstrip; SYSCTL_INT(_dev_netmap, OID_AUTO, ix_crcstrip, CTLFLAG_RW, &ix_crcstrip, 0, "NIC strips CRC on rx frames"); SYSCTL_INT(_dev_netmap, OID_AUTO, ix_rx_miss, CTLFLAG_RW, &ix_rx_miss, 0, "potentially missed rx intr"); SYSCTL_INT(_dev_netmap, OID_AUTO, ix_rx_miss_bufs, CTLFLAG_RW, &ix_rx_miss_bufs, 0, "potentially missed rx intr bufs"); static void set_crcstrip(struct ixgbe_hw *hw, int onoff) { /* crc stripping is set in two places: * IXGBE_HLREG0 (modified on init_locked and hw reset) * IXGBE_RDRXCTL (set by the original driver in * ixgbe_setup_hw_rsc() called in init_locked. * We disable the setting when netmap is compiled in). * We update the values here, but also in ixgbe.c because * init_locked sometimes is called outside our control. */ uint32_t hl, rxc; hl = IXGBE_READ_REG(hw, IXGBE_HLREG0); rxc = IXGBE_READ_REG(hw, IXGBE_RDRXCTL); if (netmap_verbose) nm_prinf("%s read HLREG 0x%x rxc 0x%x", onoff ? "enter" : "exit", hl, rxc); /* hw requirements ... */ rxc &= ~IXGBE_RDRXCTL_RSCFRSTSIZE; rxc |= IXGBE_RDRXCTL_RSCACKC; if (onoff && !ix_crcstrip) { /* keep the crc. Fast rx */ hl &= ~IXGBE_HLREG0_RXCRCSTRP; rxc &= ~IXGBE_RDRXCTL_CRCSTRIP; } else { /* reset default mode */ hl |= IXGBE_HLREG0_RXCRCSTRP; rxc |= IXGBE_RDRXCTL_CRCSTRIP; } if (netmap_verbose) nm_prinf("%s write HLREG 0x%x rxc 0x%x", onoff ? "enter" : "exit", hl, rxc); IXGBE_WRITE_REG(hw, IXGBE_HLREG0, hl); IXGBE_WRITE_REG(hw, IXGBE_RDRXCTL, rxc); } static void ixgbe_netmap_intr(struct netmap_adapter *na, int onoff) { struct ifnet *ifp = na->ifp; struct adapter *adapter = ifp->if_softc; IXGBE_CORE_LOCK(adapter); if (onoff) { ixgbe_enable_intr(adapter); // XXX maybe ixgbe_stop ? } else { ixgbe_disable_intr(adapter); // XXX maybe ixgbe_stop ? } IXGBE_CORE_UNLOCK(adapter); } /* * Register/unregister. We are already under netmap lock. * Only called on the first register or the last unregister. */ static int ixgbe_netmap_reg(struct netmap_adapter *na, int onoff) { struct ifnet *ifp = na->ifp; struct adapter *adapter = ifp->if_softc; IXGBE_CORE_LOCK(adapter); adapter->stop_locked(adapter); if (!IXGBE_IS_VF(adapter)) set_crcstrip(&adapter->hw, onoff); /* enable or disable flags and callbacks in na and ifp */ if (onoff) { nm_set_native_flags(na); } else { nm_clear_native_flags(na); } adapter->init_locked(adapter); /* also enables intr */ if (!IXGBE_IS_VF(adapter)) set_crcstrip(&adapter->hw, onoff); // XXX why twice ? IXGBE_CORE_UNLOCK(adapter); return (ifp->if_drv_flags & IFF_DRV_RUNNING ? 0 : 1); } /* * Reconcile kernel and user view of the transmit ring. * * All information is in the kring. * Userspace wants to send packets up to the one before kring->rhead, * kernel knows kring->nr_hwcur is the first unsent packet. * * Here we push packets out (as many as possible), and possibly * reclaim buffers from previously completed transmission. * * The caller (netmap) guarantees that there is only one instance * running at any time. Any interference with other driver * methods should be handled by the individual drivers. */ static int ixgbe_netmap_txsync(struct netmap_kring *kring, int flags) { struct netmap_adapter *na = kring->na; struct ifnet *ifp = na->ifp; struct netmap_ring *ring = kring->ring; u_int nm_i; /* index into the netmap ring */ u_int nic_i; /* index into the NIC ring */ u_int n; u_int const lim = kring->nkr_num_slots - 1; u_int const head = kring->rhead; /* * interrupts on every tx packet are expensive so request * them every half ring, or where NS_REPORT is set */ u_int report_frequency = kring->nkr_num_slots >> 1; /* device-specific */ struct adapter *adapter = ifp->if_softc; struct tx_ring *txr = &adapter->tx_rings[kring->ring_id]; int reclaim_tx; bus_dmamap_sync(txr->txdma.dma_tag, txr->txdma.dma_map, BUS_DMASYNC_POSTREAD); /* * First part: process new packets to send. * nm_i is the current index in the netmap ring, * nic_i is the corresponding index in the NIC ring. * The two numbers differ because upon a *_init() we reset * the NIC ring but leave the netmap ring unchanged. * For the transmit ring, we have * * nm_i = kring->nr_hwcur * nic_i = IXGBE_TDT (not tracked in the driver) * and * nm_i == (nic_i + kring->nkr_hwofs) % ring_size * * In this driver kring->nkr_hwofs >= 0, but for other * drivers it might be negative as well. */ /* * If we have packets to send (kring->nr_hwcur != kring->rhead) * iterate over the netmap ring, fetch length and update * the corresponding slot in the NIC ring. Some drivers also * need to update the buffer's physical address in the NIC slot * even NS_BUF_CHANGED is not set (PNMB computes the addresses). * * The netmap_reload_map() calls is especially expensive, * even when (as in this case) the tag is 0, so do only * when the buffer has actually changed. * * If possible do not set the report/intr bit on all slots, * but only a few times per ring or when NS_REPORT is set. * * Finally, on 10G and faster drivers, it might be useful * to prefetch the next slot and txr entry. */ nm_i = kring->nr_hwcur; if (nm_i != head) { /* we have new packets to send */ nic_i = netmap_idx_k2n(kring, nm_i); __builtin_prefetch(&ring->slot[nm_i]); __builtin_prefetch(&txr->tx_buffers[nic_i]); for (n = 0; nm_i != head; n++) { struct netmap_slot *slot = &ring->slot[nm_i]; u_int len = slot->len; uint64_t paddr; void *addr = PNMB(na, slot, &paddr); /* device-specific */ union ixgbe_adv_tx_desc *curr = &txr->tx_base[nic_i]; struct ixgbe_tx_buf *txbuf = &txr->tx_buffers[nic_i]; int flags = (slot->flags & NS_REPORT || nic_i == 0 || nic_i == report_frequency) ? IXGBE_TXD_CMD_RS : 0; /* prefetch for next round */ __builtin_prefetch(&ring->slot[nm_i + 1]); __builtin_prefetch(&txr->tx_buffers[nic_i + 1]); NM_CHECK_ADDR_LEN(na, addr, len); if (slot->flags & NS_BUF_CHANGED) { /* buffer has changed, reload map */ netmap_reload_map(na, txr->txtag, txbuf->map, addr); } slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED); /* Fill the slot in the NIC ring. */ /* Use legacy descriptor, they are faster? */ curr->read.buffer_addr = htole64(paddr); curr->read.olinfo_status = 0; curr->read.cmd_type_len = htole32(len | flags | IXGBE_ADVTXD_DCMD_IFCS | IXGBE_TXD_CMD_EOP); /* make sure changes to the buffer are synced */ bus_dmamap_sync(txr->txtag, txbuf->map, BUS_DMASYNC_PREWRITE); nm_i = nm_next(nm_i, lim); nic_i = nm_next(nic_i, lim); } kring->nr_hwcur = head; /* synchronize the NIC ring */ bus_dmamap_sync(txr->txdma.dma_tag, txr->txdma.dma_map, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE); /* (re)start the tx unit up to slot nic_i (excluded) */ IXGBE_WRITE_REG(&adapter->hw, txr->tail, nic_i); } /* * Second part: reclaim buffers for completed transmissions. * Because this is expensive (we read a NIC register etc.) * we only do it in specific cases (see below). */ if (flags & NAF_FORCE_RECLAIM) { reclaim_tx = 1; /* forced reclaim */ } else if (!nm_kr_txempty(kring)) { reclaim_tx = 0; /* have buffers, no reclaim */ } else { /* * No buffers available. Locate previous slot with * REPORT_STATUS set. * If the slot has DD set, we can reclaim space, * otherwise wait for the next interrupt. * This enables interrupt moderation on the tx * side though it might reduce throughput. */ struct ixgbe_legacy_tx_desc *txd = (struct ixgbe_legacy_tx_desc *)txr->tx_base; nic_i = txr->next_to_clean + report_frequency; if (nic_i > lim) nic_i -= lim + 1; // round to the closest with dd set nic_i = (nic_i < kring->nkr_num_slots / 4 || nic_i >= kring->nkr_num_slots*3/4) ? 0 : report_frequency; reclaim_tx = txd[nic_i].upper.fields.status & IXGBE_TXD_STAT_DD; // XXX cpu_to_le32 ? } if (reclaim_tx) { /* * Record completed transmissions. * We (re)use the driver's txr->next_to_clean to keep * track of the most recently completed transmission. * * The datasheet discourages the use of TDH to find * out the number of sent packets, but we only set * REPORT_STATUS in a few slots so TDH is the only * good way. */ nic_i = IXGBE_READ_REG(&adapter->hw, IXGBE_IS_VF(adapter) ? IXGBE_VFTDH(kring->ring_id) : IXGBE_TDH(kring->ring_id)); if (unlikely(nic_i >= kring->nkr_num_slots)) { nm_prerr("TDH wrap at idx %d", nic_i); nic_i -= kring->nkr_num_slots; } if (nic_i != txr->next_to_clean) { /* some tx completed, increment avail */ txr->next_to_clean = nic_i; kring->nr_hwtail = nm_prev(netmap_idx_n2k(kring, nic_i), lim); } } return 0; } /* * Reconcile kernel and user view of the receive ring. * Same as for the txsync, this routine must be efficient. * The caller guarantees a single invocations, but races against * the rest of the driver should be handled here. * * On call, kring->rhead is the first packet that userspace wants * to keep, and kring->rcur is the wakeup point. * The kernel has previously reported packets up to kring->rtail. * * If (flags & NAF_FORCE_READ) also check for incoming packets irrespective * of whether or not we received an interrupt. */ static int ixgbe_netmap_rxsync(struct netmap_kring *kring, int flags) { struct netmap_adapter *na = kring->na; struct ifnet *ifp = na->ifp; struct netmap_ring *ring = kring->ring; u_int nm_i; /* index into the netmap ring */ u_int nic_i; /* index into the NIC ring */ u_int n; u_int const lim = kring->nkr_num_slots - 1; u_int const head = kring->rhead; int force_update = (flags & NAF_FORCE_READ) || kring->nr_kflags & NKR_PENDINTR; /* device-specific */ struct adapter *adapter = ifp->if_softc; struct rx_ring *rxr = &adapter->rx_rings[kring->ring_id]; if (head > lim) return netmap_ring_reinit(kring); /* XXX check sync modes */ bus_dmamap_sync(rxr->rxdma.dma_tag, rxr->rxdma.dma_map, BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE); /* * First part: import newly received packets. * * nm_i is the index of the next free slot in the netmap ring, * nic_i is the index of the next received packet in the NIC ring, * and they may differ in case if_init() has been called while * in netmap mode. For the receive ring we have * * nic_i = rxr->next_to_check; * nm_i = kring->nr_hwtail (previous) * and * nm_i == (nic_i + kring->nkr_hwofs) % ring_size * * rxr->next_to_check is set to 0 on a ring reinit */ if (netmap_no_pendintr || force_update) { int crclen = (ix_crcstrip || IXGBE_IS_VF(adapter) ) ? 0 : 4; nic_i = rxr->next_to_check; // or also k2n(kring->nr_hwtail) nm_i = netmap_idx_n2k(kring, nic_i); for (n = 0; ; n++) { union ixgbe_adv_rx_desc *curr = &rxr->rx_base[nic_i]; uint32_t staterr = le32toh(curr->wb.upper.status_error); if ((staterr & IXGBE_RXD_STAT_DD) == 0) break; ring->slot[nm_i].len = le16toh(curr->wb.upper.length) - crclen; ring->slot[nm_i].flags = 0; bus_dmamap_sync(rxr->ptag, rxr->rx_buffers[nic_i].pmap, BUS_DMASYNC_POSTREAD); nm_i = nm_next(nm_i, lim); nic_i = nm_next(nic_i, lim); } if (n) { /* update the state variables */ if (netmap_no_pendintr && !force_update) { /* diagnostics */ ix_rx_miss ++; ix_rx_miss_bufs += n; } rxr->next_to_check = nic_i; kring->nr_hwtail = nm_i; } kring->nr_kflags &= ~NKR_PENDINTR; } /* * Second part: skip past packets that userspace has released. * (kring->nr_hwcur to kring->rhead excluded), * and make the buffers available for reception. * As usual nm_i is the index in the netmap ring, * nic_i is the index in the NIC ring, and * nm_i == (nic_i + kring->nkr_hwofs) % ring_size */ nm_i = kring->nr_hwcur; if (nm_i != head) { nic_i = netmap_idx_k2n(kring, nm_i); for (n = 0; nm_i != head; n++) { struct netmap_slot *slot = &ring->slot[nm_i]; uint64_t paddr; void *addr = PNMB(na, slot, &paddr); union ixgbe_adv_rx_desc *curr = &rxr->rx_base[nic_i]; struct ixgbe_rx_buf *rxbuf = &rxr->rx_buffers[nic_i]; if (addr == NETMAP_BUF_BASE(na)) /* bad buf */ goto ring_reset; if (slot->flags & NS_BUF_CHANGED) { /* buffer has changed, reload map */ netmap_reload_map(na, rxr->ptag, rxbuf->pmap, addr); slot->flags &= ~NS_BUF_CHANGED; } curr->wb.upper.status_error = 0; curr->read.pkt_addr = htole64(paddr); bus_dmamap_sync(rxr->ptag, rxbuf->pmap, BUS_DMASYNC_PREREAD); nm_i = nm_next(nm_i, lim); nic_i = nm_next(nic_i, lim); } kring->nr_hwcur = head; bus_dmamap_sync(rxr->rxdma.dma_tag, rxr->rxdma.dma_map, BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE); /* * IMPORTANT: we must leave one free slot in the ring, * so move nic_i back by one unit */ nic_i = nm_prev(nic_i, lim); IXGBE_WRITE_REG(&adapter->hw, rxr->tail, nic_i); } return 0; ring_reset: return netmap_ring_reinit(kring); } /* * The attach routine, called near the end of ixgbe_attach(), * fills the parameters for netmap_attach() and calls it. * It cannot fail, in the worst case (such as no memory) * netmap mode will be disabled and the driver will only * operate in standard mode. */ void ixgbe_netmap_attach(struct adapter *adapter) { struct netmap_adapter na; bzero(&na, sizeof(na)); na.ifp = adapter->ifp; na.na_flags = NAF_BDG_MAYSLEEP; na.num_tx_desc = adapter->num_tx_desc; na.num_rx_desc = adapter->num_rx_desc; na.nm_txsync = ixgbe_netmap_txsync; na.nm_rxsync = ixgbe_netmap_rxsync; na.nm_register = ixgbe_netmap_reg; na.num_tx_rings = na.num_rx_rings = adapter->num_queues; na.nm_intr = ixgbe_netmap_intr; netmap_attach(&na); } /* end of file */